The invention relates to quick-opening valve mechanism for release of pressurized gas to suppress a fast-developing fire or explosion, as from ignition of a hydrocarbon or the like fuel.
The inner volume of a military tank is illustrative of an environment that is prone to disastrous consequences in the event of a hydrocarbon fire, as when a fuel tank has been ruptured by an armor-piercing shell. Detector devices exist with capability of generating an electrical-signal output at onset of fire, and the means exists for liquified storage of suppressant gas under pressure, for discharge to suppress the fire in response to the detector signal output. However, valve mechanism for responding to the detector signal and for releasing the suppressant gas has been far from reliable, to the extent that the release of suppressant gas may or may not be in time to avert disastrous consequences.
It is believed that one reason for unreliability of such present valve mechanisms is that controlled operation of the valve member from normally closed to full-open position has relied upon pressure-responsive means including one or more pilot-operated stages, for example, a solenoid-operated pilot valve, which releases pressure fluid to control valve-member displacement. Such arrangements involve displacements, multiple seals, and mechanical friction which make it difficult, if not impossible, to obtain consistent performance, as to speed of valve opening, and as to time delay until valve opening, for a given valve, and from one to the next valve in a given production lot.
Other devices have sought entirely to eliminate valve action, by employing a frangible diaphragm to maintain normal closure of a pressurized suppressant gas supply, with release and discharge by reason of an explosive cap which is fired to break the diaphragm. But such devices are difficult to clean, for recharge purposes, and they are not safe, in that they may be accidentally operated in the event of nearby radio transmissions.